Barks are generally considered wastes from commercial manufacturers.
Exploded wood is known, and so far, has been considered a curiosity rather than a tool to obtain new products having particular properties.
The prior art discloses steam explosion of wood, and also bark, but in order to extract the oils and sugars inherent to trees (wood and barks). These oils are for instance: fatty acids, fatty alcohols, fatty ketones, aromatic esters, aromatic acids, phenols and polyphenols, alkanes, alkenes. Normally oils and sugars represent about 30% of which about 15 to 20% are sugars. These sugars and phenols may be water-extracted and the oils solvent-extracted.
There is also disclosed in Canadian Patent 1,213,711 as invented by Shen, Ku-Cheng, dated Nov. 12, 1986, a process for converting lignocellulosic materials into composite products whereby, as stated on Page 4, penultimate paragraph, the inventor has disclosed that free sugars can be generated from hemicellulose in any lignocellulosic materials and be utilized as a bonding agent for reconstituted composite products. The inventor converts hemicellulose into free sugars, carbohydrates or saccharides by auto-hydrolysis.
As stated on Page 6 of the patent, "First, acetic acid is formed by cleavage of acetyl side chains, and the weak acidic environment thus created is sufficient to promote hydrolysis of hemicellulose. The depolymerization reaction is believed to be a sequential reaction. During the initial phase of the reaction process, random attack by acid in hemicellulose chains produces oligomers of varying degrees of polymerization. The oligomers are further hydrolyzed to monomers which are further degraded to furfural and other decomposition products. Simultaneously, the lignin portion of lignocellulosic materials is also decomposed and hydrolyzed to low molecular weight lignin and lignin products Only the cellulose remains relatively unchanged. The steam-treated lignocellulosic materials normally have about 20 to 30% of water solubles which contain sugars, sugar polymers, dehydrated carbohydrates, furfural products, lignin products. The free sugars, furfural, and other decomposition products are essential parts of the present invention. When chemically transformed under heat and pressure, they would thermoset and crosslink into a polymeric substance acting as both a bonding and bulking agent for the reconstituted composite products from the steam treated lignocellulosic materials."